The ability to safely and efficiently perform maintenance on rotor hubs has been a continual goal of the engineering service industry.
Historically, rotor hubs have been maintained through time consuming, potentially dangerous processes. For example, wind turbine rotors are currently removed and suspended during routine maintenance with several cranes working in conjunction. Similarly, wind turbine rotors have traditionally been removed and positioned for placement on a central stand in close proximity to the ground. While cranes continue to suspend the rotor hub assembly, workmen perform maintenance on the rotor hub. When finally placed on the central stand, the large scale of a typical wind turbine in combination with a lack of support for protruding blades creates potential hazards for workmen's continued maintenance of the rotor hub. As the rotor is pivotally connected to the ground via a small stand in the current maintenance process, any wind can create torque that violently shifts the rotor hub assembly. Likewise, the current maintenance techniques require workmen to spend extended amounts of time on their back under the suspended load. The slightest failure in the suspension of the rotor hub or in the rotor hub itself is potentially devastating to the workmen.
With tedious maintenance being performed on wind turbines several times a year, the dangers of maintenance worker safety is compounded by the structural risks associated with current maintenance techniques. The current method of suspending a rotor hub with multiple cranes stresses the joints, increases maintenance time, and decreases the useful life. A lack of support for individual rotor blades creates stresses throughout the rotor assembly as well as safety hazards for workmen under the rotor and operating suspension cranes. Further, a close proximity to the ground does not provide workers with enough room to efficiently assess the rotor hub and perform scheduled maintenance.
The combination of a large suspended load with inefficient area to perform maintenance generates a volatile situation that unnecessarily creates hazards for workmen and the rotor hub assembly. Accordingly, there is a continuing need for improved systems for maintaining rotor hubs.